It is known to spray slurries of hydrated lime into the discharging flue gases from coal powered furnaces or boilers, such as in electric power plants, for the purpose of capturing, reaction with, and removing sulfur dioxide from the gases prior to discharge to the atmosphere. To effectively scrub sulfur dioxide from such gases, it is necessary that the slurry be finely atomized into liquid particles of about 100 microns or less in diameter. It also is desirable that spray particles be of such small size in order to enhance drying prior to impinging upon the flue duct work so as to prevent build-up and corrosion. Heretofore, problems have been incurred in achieving sufficient and consistent atomization of such lime slurries. Existing spraying systems further have required relatively large capacity pressurized air sources, which are not always readily available or economically feasible, and the high speed direction of such slurries through the spray nozzle assemblies tends to create excessive wear to exposed surfaces of the nozzle.